Theissen angry with Head criticism.

The already tense relationship between Williams and engine supplier BMW took another twist as the latter's Mario Theissen spoke out on negative comments made about him by Patrick Head in an interview with an Italian journalist.

Head was critical of the team's relationship with BMW, and was reported as saying that Dr Theissen was dishonest. The subsequent storm has come at an extremely bad time as the future of the relationship between BMW and Williams is under review, with the Germans rumoured to be considering a buy-out of rival Sauber.

"I heard about this interview when I arrived here," Theissen said from the Canadian Grand prix, "I went over to Frank [Williams] and told him I was very surprised about that. Frank said he was surprised as well.

"How would you expect me to react to it? Maybe it was intended as an attempt to foster new relationships, to motivate all the people here at the track, to encourage BMW to extend the partnership, or promote me personally. Maybe the journalist asked the wrong question!

"It is certainly not helpful to have comments like this in an environment like F1. If the comment was from a commentator, you could just ignore it, but Patrick is a part team owner and he carries responsibilities for his people and for his team. If you see the people out here [in Montreal], Sam Michael has to do the real job out here, and he does that job very well.

"His engineers and our engineers are working together and making progress together. The working relationship is very good, and I think those guys deserve support rather than stumbling blocks put in their way. And certainly, comments like this are not useful on a race weekend."

Theissen said he had not spoken to Head since the story broke, and had no intention of calling him to talk about it: "No, I don't think so,' was his dismissive response to that question.

Meanwhile, Sir Frank Williams went to great lengths to distance himself from his long-time partner's opinions.

"I can assure you that, in all my time with Mario, I've never, ever wanted to say he was dishonest - because he's isn't," said the veteran team boss, "The remarks made by Patrick were private remarks and absolutely do not reflect the position of this company with respect to Mario, and just as importantly, to BMW.

"One particular remark was taken slightly out of context, and I want to make it totally and absolutely clear that this remark, in whatever context it was used, does not reflect the position of me, or our attitude to Mario or our attitude to BMW."